1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/ftrace.h> 3 #include <linux/init.h> 4 #include <linux/slab.h> 5 #include <linux/mm_types.h> 6 #include <linux/pgtable.h> 7 8 #include <asm/bugs.h> 9 #include <asm/cacheflush.h> 10 #include <asm/idmap.h> 11 #include <asm/page.h> 12 #include <asm/smp_plat.h> 13 #include <asm/suspend.h> 14 #include <asm/tlbflush.h> 15 16 extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid); 17 extern void cpu_resume_mmu(void); 18 19 #ifdef CONFIG_MMU 20 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 21 { 22 struct mm_struct *mm = current->active_mm; 23 u32 __mpidr = cpu_logical_map(smp_processor_id()); 24 int ret; 25 26 if (!idmap_pgd) 27 return -EINVAL; 28 29 /* 30 * Function graph tracer state gets incosistent when the kernel 31 * calls functions that never return (aka suspend finishers) hence 32 * disable graph tracing during their execution. 33 */ 34 pause_graph_tracing(); 35 36 /* 37 * Provide a temporary page table with an identity mapping for 38 * the MMU-enable code, required for resuming. On successful 39 * resume (indicated by a zero return code), we need to switch 40 * back to the correct page tables. 41 */ 42 ret = __cpu_suspend(arg, fn, __mpidr); 43 44 unpause_graph_tracing(); 45 46 if (ret == 0) { 47 cpu_switch_mm(mm->pgd, mm); 48 local_flush_bp_all(); 49 local_flush_tlb_all(); 50 check_other_bugs(); 51 } 52 53 return ret; 54 } 55 #else 56 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 57 { 58 u32 __mpidr = cpu_logical_map(smp_processor_id()); 59 int ret; 60 61 pause_graph_tracing(); 62 ret = __cpu_suspend(arg, fn, __mpidr); 63 unpause_graph_tracing(); 64 65 return ret; 66 } 67 #define idmap_pgd NULL 68 #endif 69 70 /* 71 * This is called by __cpu_suspend() to save the state, and do whatever 72 * flushing is required to ensure that when the CPU goes to sleep we have 73 * the necessary data available when the caches are not searched. 74 */ 75 void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) 76 { 77 u32 *ctx = ptr; 78 79 *save_ptr = virt_to_phys(ptr); 80 81 /* This must correspond to the LDM in cpu_resume() assembly */ 82 *ptr++ = virt_to_phys(idmap_pgd); 83 *ptr++ = sp; 84 *ptr++ = virt_to_phys(cpu_do_resume); 85 86 cpu_do_suspend(ptr); 87 88 flush_cache_louis(); 89 90 /* 91 * flush_cache_louis does not guarantee that 92 * save_ptr and ptr are cleaned to main memory, 93 * just up to the Level of Unification Inner Shareable. 94 * Since the context pointer and context itself 95 * are to be retrieved with the MMU off that 96 * data must be cleaned from all cache levels 97 * to main memory using "area" cache primitives. 98 */ 99 __cpuc_flush_dcache_area(ctx, ptrsz); 100 __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr)); 101 102 outer_clean_range(*save_ptr, *save_ptr + ptrsz); 103 outer_clean_range(virt_to_phys(save_ptr), 104 virt_to_phys(save_ptr) + sizeof(*save_ptr)); 105 } 106 107 extern struct sleep_save_sp sleep_save_sp; 108 109 static int cpu_suspend_alloc_sp(void) 110 { 111 void *ctx_ptr; 112 /* ctx_ptr is an array of physical addresses */ 113 ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL); 114 115 if (WARN_ON(!ctx_ptr)) 116 return -ENOMEM; 117 sleep_save_sp.save_ptr_stash = ctx_ptr; 118 sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr); 119 sync_cache_w(&sleep_save_sp); 120 return 0; 121 } 122 early_initcall(cpu_suspend_alloc_sp); 123